The Flow Cytometry Core Facility of the National Human Genome Research Institute has the goal of providing all NHGRI investigators with access to high quality flow cytometry services. The Core serves to enhance the scope and quality of scientific research performed by the Institute. For FY2013 the Flow Cytometry Core was staffed by Stacie Anderson (Core Director, 100% effort, GMBB), and Martha Kirby (100% effort, GMBB). The Flow Cytometry Core is staffed Monday through Friday. Access to the Flow Core after regular working hours and on weekends/holidays is possible for authorized investigators through Accutech card readers. The NHGRI Flow Cytometry Core currently maintains two BD FACSArias that are primarily used for sorting cells. In 2012 we purchased a 561nm laser for one Aria. This laser was installed in April 2013 and addresses the need to discriminate fluorochromes, such as PE and fluorescent proteins, such as DsRed and mCherry. Otherwise, each FACSAria is configured with three lasers and can measure up to nine fluorescent parameters as well as physical parameters (size and granularity). Among the various applications over the past year, these sorting capabilities have been used for isolation of tissue cell populations for animal transplantation experiments; isolation of blood cell sub-populations for analysis of functional cellular properties and gene transcription profiles, as well as high throughput screening of enhancer regions. The FACSArias typically have a two week sign up waiting time and are currently used at capacity. For direct flow cytometry analysis applications not involving cell sorting, the Flow Core offers one BD FACSCalibur and one BD LSRII. The FACSCalibur can measure up to four fluorescent parameters, and are routinely used for data acquisition and pre-sort analysis. Typical uses of the FACSCalibur include analysis of GFP expression and cell cycle, as well as mutagenesis screening. The BD LSRII uses digital electronics and Diva software similar to the Aria and is used to perform 9-color analyses. This allows investigators to characterize cells in more detail before sorting on the Aria. The instrument is equipped with a High Throughput Sample (HTS) device that gives the investigator the ability to analyze many samples in 96 well plate format without the need of sitting at the instrument during the acquisition procedure. The BD LSRII is available during regular Core hours as well as after hours and on weekends. The Flow Core maintains a laser scanning cytometer (LCS). The LSC uses laser-based opto-electronics and automated analysis capabilities to simultaneously and rapidly measure biochemical constituents and evaluate cell morphologies. Current applications (100%) are focused on zebra fish projects including drug screens and blood development. The Flow Core also maintains a Miltenyi Auto MACS that is used for magnetic cell separations. The AutoMACS is often used as a pre-enrichment step prior to sorting on a flow cytometer. Over the past year, the services and capabilities of the NHGRI Flow Core have been taken advantage of by over 60 trainees from 5 Branches/14 Sections in the Institute LSRII 265 scheduled appointments Calibur 551 scheduled appointments Arias 327 scheduled appointments icys 35 scheduled appointments TOTAL scheduled appointments for FY2013 1178 In addition, the Flow Core continued to maintain CLIA accreditation in support of immunophenotyping and protein expression studies used in NHGRI clinical research protocols.